There are always exceptions on that particular part of the forum rules.
I can recall searching and reading through about this in the past because it’s very common to see refer links on ANN threads of casinos and campaign manager can also do share such link.
https://bitcointalk.org/index.php?topic=5172343.msg52557780#msg52557780In the thread above where 1miau discuss about ref link their was exceptions pointed out
I know it is against the rules to post referral links only.
-snip-
Correct,
but it's allowed if it isn't spam.
The only exception is if you're the owner or representative of the gambling website
and you're posting it as the official thread of your casino, that's normally tolerated because it isn't ref code spamming.
Example:
wetsuit's thread - with "
?r=4" as his ref link.
However,
the description of your "review" is one of the example of ref link spam.